Gate valves are linear motion valves used for isolating or regulating fluid flow in pipes. There are two main types of gate valves based on their configuration and use – manual gate valves and underground gate valves.
1. Manual Gate Valve
A manual gate valve has an operating mechanism or gear that allows manual operation with a handwheel or lever. This enables an operator to open and close the valve by rotating the handwheel or moving the lever.
China Manual gate valves are used for isolating or regulating flow in process lines where easy manual access is available. They are also used as local shut-off valves at equipment connections.
Manual gate valves are generally available in nominal sizes from 1 to 48 inches. They are made from materials like cast iron, brass, bronze and stainless steel based on the application requirements. Boltless bonnet designs are commonly used for easier maintenance.
The main advantages of manual gate valves
The main advantages of manual gate valves are their simple design, low cost and easy operation. However, they require manual intervention to operate and cannot be controlled remotely.
2. Underground Gate Valve
An underground gate valve is specifically designed to be installed below grade or underground, often inside a valve box or vault. The operating mechanism of an underground gate valve is extended with a valve key or stem to allow access from above ground level.
Underground gate valves are used for isolating or regulating flow in underground pipelines that carry water, wastewater, gas or other fluids. They enable access and operation even after the pipeline is buried.
These valves are made from corrosion resistant materials like cast iron, ductile iron, stainless steel or composite. 2 inch to 24 inch nominal sizes are commonly available. Special encapsulated or lubricated stem designs are used to prevent ingress of soil and moisture.
The key benefits of underground gate valves
The key benefits of underground gate valves are their ability to be installed and operated below ground. However, they require a valve box or vault for operation and access, which increases installation cost.